Die



March 31, 1931. B. A. LANGE 1,798,475

DIE

Original Filed Nov. 26, 192,6

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Patented Mar. 31, 1931 UNITED STTES BERTHOLD A. LANGE, OF ST. LOUIS, MISSOURI DIE Original application filed November 26, 1926, Serial No. 150,840. Divided and this application filed November 18, 1929.

This invention relates to a die for creasing a blank of pasteboard, fiberboard, strawboard, or similar material to provide a flexile seam on which the blank can be readily bent without fracture into box formation.

The present application is a division of the present inventors prior application for United States patent, Serial No. 150,840, filed November 26, 1926, for an improvement in box-corners.

The principal purpose of the present invention is to provide a die that will crease the box blank with a minimum strain on the material to form a seam for the corner. Other objects,

advantages and desirable features of the invention will appear in the course of the following description of two illustrative embodiments of the spirit of the invention.

In the accompanying drawing forming 29 part of this specification, in which like numbers of reference denote like parts wherever they occur-- Figure 1 is an end view of a pair of reciprocating dies made in accordance with the 25 present invention;

Figure 2 is an elevation of a pair of rotary dies made in accordance with the present invention; and

Figure 3 is a fragmentary View, showing the dies brought closer together than in Figures 1 and 2, in order to accommodate them to stiffer and more resistant work material.

Referring to Figure 1, the male die 1 is provided with a die face 2 that presents a pair of spaced flanges or projections 3 and 4 that define a groove or depression 5' therebetween; and the female die 6 is provided with a die face 7 that presents a series of flangesor projections 8, 9, and 10 that define relatively spaced-apart depressions 11 and 12 that are alined with the said projections 3 and 4, respectively, of the die 1. The end projections 8 and 10 rise higher than the r intermediate projection 9. The sheet of box material 13 is placed between the dies and the dies brought toward one another until they crease the material to the desired depth.

It will be observed that the material is not scored, partly removed, or otherwise weak- Serial No. 408,055.

ened to form the seam, but is upset without cutting away or breaking the fiber, and that no more material than is necessary for flexibility is gathered into the seam, since the flange 9 is not high enough to gather undue amount of material into the depression 5, or to exert enough tension on the material to weaken or break the fibers during the formation of the seam.

The dies need not necessarily be of thereciprocating type shown in Figure 1, for the material can be creased as well by passing it between a pair of rotary dies 14 and 15, respectively, as shown in Figure 2. The dies are afixed to shafts 16, j ournaled in bearings 17 in a suitable framework 18. The cylindrical faces 19 and 20 of the dies 14 and 15, respectively, are provided with respective annular flanges 21, 22, 23, 24, and and annu- I, lar grooves 26, 27 and 28, which correspond 1:; with the flanges 3, 4, 8,9, and 10, respectively, and with the grooves 5, 11, and 12, respectively, of the blocks 1 and The degree of proximity of the dies to each other for creasing the work material or blank to a given depth is governed by the quality, character, and thickness of the material, and its tendency to recover its original shape after having been upset by the dies. The depth of the crease in the material, of course, must be such that the material can be bent about the crease into boX formation, without breaking. The nature of the blank or work material in the dies of Figures 1 and 2 is such that the flanges of one die need not enter the depressions of its co-operating die to produce creases of the depth shown. However, with different material, it may be desirable to have the dies approach closer to one another, as shown in Figure 3, wherein the flanges 21 and 22 of the die 14 enter the grooves or depressions 20 of the die 15, thereby producing deeper creases in the material. By reason of the projection 9 or 24 being lower than the projections 8 and 10, or 23 and 25, respectively, the strain on the material, in creasing, is reduced, and less material is used in the crease. The upper faces of the flanges or beads 9 and 24 may be rounded to further re- 10 duce the strain on the material.

Having thus fully described this invention, I hereby reserve the benefit of all changes in form, arrangement, order, or use of parts, as it is evident that many minor changes may be made therein without departing from the spirit of this invention or the scope of the following claims.

I claim:

1. A pair of dies for creasing material therebetween to form flexible seams therein, one of said dies being provided with a die face presenting, at least, a pair of spaced projections defining a depression, and the other die being provided with a die face presenting a. series of projections defining relatively spaced-apart depressions that are alined with the said projections, respectively, of the firstlnentioned die, the end projections of the said series of the said other die rising higher than the remainder of the series.

2. A pair of dies for creasing material therebetween to form flexible seams therein, one of said dies being provided with a pair of spaced projections defining a depression and the other die being provided with a die face presenting a series of projections defining rel atively spaced-apart depressions that are alined with the said projections of the firstmentioned die, the central projection of said series being shorter than its companions to prevent undue extension of the material operated upon into the depression of said firstnamed die.

3. A pair of dies for creasing material therebetween to form flexible seams therein, one of said dies being provided with a pair of spaced projections defining a depression and the other die being provided with a die face presenting a series of projections defining relatively spaced-apart depressions that are alined with the said projections of the first-mentioned die, one of the projections of the second-mentioned die being shorter than its companions to prevent its entry into the depression of said first-named die whereby the material is given alternate bends with no increase in material at the intermediate bend.

In testimony whereof I hereunto afiix my signature.

BER'IHOLD A. LANGE. 

